/**
 * Copyright (c) Meta Platforms, Inc. and affiliates.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of https://github.com/facebook/react-native.
 */

export type PackagerAsset = Readonly<{
  httpServerLocation: string
  name: string
  type: string
}>

/**
 * FIXME: using number to represent discrete scale numbers is fragile in essence because of
 * floating point numbers imprecision.
 */
function getAndroidAssetSuffix(scale: number): string {
  switch (scale) {
    case 0.75:
      return 'ldpi'
    case 1:
      return 'mdpi'
    case 1.5:
      return 'hdpi'
    case 2:
      return 'xhdpi'
    case 3:
      return 'xxhdpi'
    case 4:
      return 'xxxhdpi'
    default:
      return ''
  }
}

// See https://developer.android.com/guide/topics/resources/drawable-resource.html
const drawableFileTypes = new Set<string>(['gif', 'jpeg', 'jpg', 'png', 'webp', 'xml'])

function getAndroidResourceFolderName(asset: PackagerAsset, scale: number): string {
  if (!drawableFileTypes.has(asset.type)) {
    return 'raw'
  }
  const suffix = getAndroidAssetSuffix(scale)
  if (!suffix) {
    throw new Error(
      `Don't know which android drawable suffix to use for asset: ${JSON.stringify(asset)}`
    )
  }
  const androidFolder = `drawable-${suffix}`
  return androidFolder
}

function getResourceIdentifier(asset: PackagerAsset): string {
  const folderPath = getBasePath(asset)
  return `${folderPath}/${asset.name}`
    .toLowerCase()
    .replace(/\//g, '_') // Encode folder structure in file name
    .replace(/([^a-z0-9_])/g, '') // Remove illegal chars
    .replace(/^assets_/, '') // Remove "assets_" prefix
}

function getBasePath(asset: PackagerAsset): string {
  let basePath = asset.httpServerLocation
  if (basePath[0] === '/') {
    basePath = basePath.substr(1)
  }
  return basePath
}

export default {
  getAndroidAssetSuffix,
  getAndroidResourceFolderName,
  getResourceIdentifier,
  getBasePath,
}
